The invention relates to a discharge tube for a fuel can.
A discharge tube of this kind is described in German Patent DE-PS 2,514,278. The tube cross section is divided by the partition wall so that separate channels are available for the fuel flowing out and the air stream flowing back into the can as a compensation, thus making pouring out easier. The bellows-type central section makes it possible to reach even unfavorably located filler pipes easily. In the known discharge tube, the partition wall is designed to extend through this central section as well, making it necessary to employ a special ploy. The peripheral grooves of one tube part have namely to be arranged offset by half the spacing of the peripheral grooves of the other tube part to enable this groove arrangement to extend over the entire periphery right into the pinch-off seam. It goes without saying that the mold required to produce this discharge tube is correspondingly complicated and expensive. As is known, when a rod bends, said rod has what is called a neutral axis, which retains its length while the material on one side of it is compressed and that on the other side is stretched. In the flexible central section of the known discharge tube, however, this neutral axis cannot establish itself freely from the equilibrium of forces in the material but is forcibly established by the partition wall because this partition wall acts like a film hinge. However, this partition wall is situated in a plane which is laterally offset with respect to the central axis of the tube because the tube cross-section provided for the fuel has to be bigger than that for the returning air. As a result, the forcibly established neutral axis of the flexible central section is not where it would naturally be located. When the known discharge tube is bent, the bellows-type wall regions on each side of the partition wall are therefore stressed in a non-uniform manner. It is also observed that bending is concentrated on a central third of the total length of the bellows-type central section, while the rest of the central section provided with peripheral grooves remains virtually unchanged. Flexibility is thus restricted. In other words, given a specified amount of bending, the material is more highly stressed at some points, thereby jeopardizing its durability.